Apparatus for teaching geography and astrography



October 25, 191-3.

DRAWING A careful search has "been made this day for the originaldrawing or a photolithographic ccpy 0f the same for the purpose ofreproducing the said drawing t0 farm a part of this book, but at thistime nothing can be found from which a reproduction can be made:a

Finis D. Morris Chief of Division 38.

ROBERT PIGGO'I, OF ELK RIDGE LANDING, MARYLAND.

APPARATUS FOR TEACHING GEOGRAPHY AND ASTROGRAPHY.

Specification of Letters Patent No. 2,426,, dated January 17, 1842.

To all whom it may concern:

Be it known that I, ROBERT PIGGOT, of Elk Ridge Landing, in Anne Arundelcounty, in the State of Maryland, minister of the Gospel, have inventedcertain Improvements in Apparatus for Teaching Geography andAstrography; and I do hereby declare that the following is a full andexact description thereof.

This improved apparatus consists principally of spheres, of hemispheres,or other portions of spheres, and of plain surfaces, which are to havedrawn, out, or indented, upon them lines representing meridians,parallels of latitude, and any of the greater, or the lesser circlesusually depicted, or delineated, upon celestial and terrestrial globes,maps, and charts; said spheres, or plane surfaces, being also covered,by means of a dark-colored paint, varnish, or other adhesive substance,with any fine, earthy powder which shall give to them the properties ofartificial slates, so that by means of white crayons, or other suitablesubstances, lines and figures may be readily drawn upon them, andreadily erased; or such surfaces may be prepared and finished of a lightcolor, so that they may be drawn upon by a lead pencil, and the pencillines erased by india rubber.

In the accompanying drawing, Figure 1, is a representation of the kindof sphere wl1icl1 I employ both for geographical and astrographicaldelineations.

A, A, is a hollow globe, of a fourth of an inch in thickness, more orless, and which may be made of wood, paper, or other light material;this globe I construct so that it may be separated at the equator, or inany great circle, being, when the two parts are placed together,retained by means of a groove, rabbet, or other suitable device; andhaving grooved indentations on its outer surface, corresponding with thegreater and the lesser circles usually delineated on the terrestrialglobe. When the two parts are separated, the interior will present thewhole, or any desired part, of thelines ordinarily drawn on thecelestial globe; such lines, both on the exterior and interior, beingindented, or cut, to a suflicient depth to be visible and tangible,after the surfaces have been covered with the slate like, or other,composition. Besides the greater and lesser circles which are to be outwithin the hollow, or celestial, sphere, I intend sometimes to cut inthe same manner, the outlines of the whole, or of a part, of therespective constellations; but for the more advanced students it will bebest to provide only the greater and lesser circles, such as those whichserve to designate the celestial latitudes and longitudes; the colures;the cliptic; the equinoctial; the tropics, and the polar circles;leaving the pupil to draw the out lines of the respectiveconstellations, as well as to mark thereon the places of the principalstars contained in them.

I use, when the terrestrial globe is the subject in hand, a standconsisting of a round piece of wood A, having a concavity in which theglobe will lie, and remain in any position in which it may be placed;or, instead of this, a stand consisting of a ring, or hoop, supported onlegs may be employed. In using this sphere, the scholar is required todraw, with the crayon, the outlines of the respective continents,islands, or other divisions of the globe, in their relative positions;the exercise being the same both with the celestrial and the terrestrialsphere, the objects to be delineated being the only difference.

Fig. 2, represents a section of the hollow globe, supposed to be madethrough its poles.

t B, B, is shown the manner in which the hemispheres may be joinedtogether by a rabbet, or other device. The respective lines in theinterior, or concave, sphere, represent some of this which are to beindented, or cut, into the surface of said interior, as permanent guidesin the operations to be performed.

Besides the spheres and hemispheres indented, or cut, so as to presentthe lines which are to guide the pupil, and so prepared as to present asurface of artificial slate, or capable of receiving pencil lines, whichmay be erased, I also provide tablets of wood, or of other lightmaterial, which are to have such lines cut, or indented, upon them asare usually delineated on maps representing the whole, one half, or anyportion, of the earth, or of the celestial sphere; such lines being ofthe kind above designated, and being projected on any of the knownsystems, or plans, and such tablets being prepared so as to formartificial slates, or other suitable surfaces, admitting of drawingsbeing made upon, and of being erased from, them at pleasure. Figs. 3,4L, 5, 6, 7 and 8, represent such tablets, with lines indented uponthem, of such kind as Will be found applicable to the purpose abovedesignated; the nature and object of these Will be perfectly obvious,and it Will be readily seen that they may be so varied as to adapt themto the requirements of the teacher, and of the pupil.

Having thus, fully pointed out the nature of my improvements in theapparatus for teaching geography and astrography, and the manner inWhich the same may be formed and used, What I claim therein as new, anddesire to secure by Letters Patent, is

The forming of celestial and terrestrial spheres, or of portionsthereof, and of the lines representing the projections of such spheresor of portions thereof, of Wood, or of other light materials, having thelines representing the greater and the lesser circles, or the outlinesof constellations, cut into such spheres, or plane surfaces, and havingthe Whole of the surfaces of such spheres, or portions of spheres, orplain surfaces, converted into artificial slates, being so coated andprepared as that pencil lines may be drawn upon, and erased from, them,

, substantially in the manner, and for the purposes, herein fully madeknown and described.

ROBERT PIGGOT. Witnesses:

THOS. P. JONES, M. J ONES.

